The pope said the Palestinian-Israeli conflict “for 60 years has been bloodying the Holy Land, causing “so many tears and so much suffering among the two peoples.”

The pope made the remarks Sunday on the steps of St. Peter’s Basilica at the end of a Mass that he concelebrated with 23 new cardinals.

In a recent letter, Chicago Cardinal Francis E. George, president of the U.S. Conference of Catholic Bishops, urged U.S. bishops to call parishes and individuals to pray for peace, especially on the Sunday before the peace conference.

The U.S.-sponsored conference opens on Tuesday, and participants include representatives from a number of Arab states.